Some larger solar collector installations include an array of sun-tracking, solar power collector assemblies. Such assemblies can be used in conjunction with photovoltaic modules, concentrated photovoltaic modules, as well as concentrated thermal solar collector devices.
Such sun-tracking collectors include hardware for automatically adjusting the position of the collector devices to track the sun as it moves across the sky. This tracking movement can be accomplished in a number of different ways. Some systems use a single axis tracking system in which the collector devices pivot about a single axis. Such single axis type tracking systems often include a drive shaft or “torque tube” which defines a single pivot axis. Other systems use multiple axes of rotation.
Because the torque tubes pivot through a limited range of rotation about the axis, conventional roller bearings are not necessary for such applications; they would be an unnecessarily large expense or such an application. Thus, some sun-tracking solar systems include other types of bearings.